In development for most of a decade, this was a mod for Freespace 2, but since the source code was released and modified, it's now a stand-alone. It was released early last year. I've probably posted about this before, I've probably tried it before, and it probably sucks. I don't know if it works on Win7. . .but the screen shots are cool. Enjoy the screen shots.
http://babylon.hard-light.net/gallery1.php
http://babylon.hard-light.net/gallery1.php